Everything Is a Harmonic Oscillator

Everything is blocks on springs. Pull the block, let go, and, as far as friction-agnostic physicists are concerned, it bounds back and forth forever. So will a pendulum bob—not just in a similar-ish way, but rigorously, quantitatively, exactly the same way. Same with water in a U-shaped tube a…http://www.lastoneminute.com/everything-is-a-harmonic-oscillator/